CGPDFDocumentReleasepdfDocument

CGPDFDocumentRef is a Core Graphics opaque type representing a PDF document. It is used to access and manipulate the content of a Portable Document Format (PDF) file within the Apple ecosystem, primarily in macOS and iOS development.

To obtain a CGPDFDocumentRef, developers typically use the CGPDFDocumentCreateWithURL or CGPDFDocumentCreateWithDataProvider functions, providing either a file URL or a data provider containing the PDF data. Once created, this reference allows for reading various properties of the PDF, such as the number of pages.

Methods associated with CGPDFDocumentRef enable access to individual pages within the document. For instance, CGPDFDocumentGetPage retrieves a CGPDFPageRef for a specific page number. This page reference can then be used to draw the page content onto a graphics context, extract text, or obtain information about the page's dimensions and rotation.

Furthermore, CGPDFDocumentRef provides access to the document's catalog and pages-related dictionaries, which are fundamental structures within the PDF specification. These lower-level accesses can be useful for advanced manipulation or inspection of PDF metadata and structure. The lifecycle of a CGPDFDocumentRef is managed through reference counting, requiring explicit release using CGPDFDocumentRelease when it is no longer needed to prevent memory leaks.